Module 4 Using TI-89 or Voyage 200 to Explore the Concept of Limit

To find the x-value of the point of intersection of y2 = 1.9 (the lower bound of the y-tolerance) and
y1= (the graph of the function), you need to specify the two curves.
Selecting the Two Intersecting Curves
To find a point of intersection of two curves, the curves must be selected. The cursor is already
on the function y1, as indicated by the small "1" in the upper right portion of the screen.
• Select the function as one of the curves by pressing
The small + shown on the graph of the function indicates that it is the first curve selected. The
cursor is on the lower horizontal line to indicate that that line is currently chosen and it is blinking
to indicate that it has not been selected. Note that "2" is shown in the upper right portion of the
screen to indicate that the current position of the cursor is on the graph of y2.
• Designate the lower line (y2) as the second curve by pressing
Specifying a Lower Bound
The TI-89 prompts you for a lower bound
• Choose a lower bound for the point of intersection by pressing and holding the key until
the cursor is to the left of the x-coordinate of the point of intersection
Any value less than the x-coordinate at the point of intersection will work.
• Select the lower bound by pressing
Notice the small right arrow at the lower bound.